Rubberized product



Patented Dec. 1937 .RUBBERIZED PRODUCE Edward G. Budd, Philadelphia, Pa., 'assignor to Edward G. Budd Manufacturing Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application December 21, 1933,

- Serial No. 703,407

This invention relates to improvements in rub- I am aware that it has heretofore beenpro- 10 posed to employ rayon in tires. The rayon thread or yarn which has hitherto been used for such purposes has been a cabled thread of about 3000 or 4000 denier, the thread being composed of a number of small threads each having twist and 15 the component threads being twisted together to form a cable, the twist being heavy. For example, it has been customary to cable five threads of about 2'75 denier and 120 filaments each and then cable three of these to produce the ultimate 20 thread, the amount of twist imparted being such that reliance for elasticity and spring return is primarily placed upon the heavy twist rather than upon the inherent physical properties of the material of the thread itself.

25 .It will be seen that with such cabled thread a great number of the filaments per unit of denier will be exposed to and impregnated with the rubber- In addition there will be a relatively large surface exposed to the rubber because of the 30 physical construction of the thread, and the surface, instead of being relatively smooth, will be indented. The case of rubber about each thread, will therefore, extend materially into the thread at spots. The net result is that the thread 85 will be less flexible and will develop considerable internal friction and heat.

I propose a thread for such purpose in which reliance is preferably placed more upon the physical properties of the material of the thread itself 40 to provide the required elasticity and spring return, than upon the twist imparted to the thread. The thread of my invention also. exposes a smaller number of filaments and a smaller surface per unit of denier to the action of the rubber. Ac-

(6 cording to my invention the thread is composed of non-adherent filaments the greater number of which, by far, are unaffected by the rubber and, therefore, left free to roll upon one another,

securing the maximum of flexibility with a minibrings up .the denier.)

than 2 which would give about approximately 1500 to approximately 2500 filaments for a 4000 denier yarn. The yarn should preferably have a dry strength of two'grams per denier or more (dry state) with an elongation (dry state) of from about8%'to about 12%. The elongation may be increased at some sacrifice in strength.

I obtain the'fullest advantage of my inven tion when using a single thread as just above described, the thread. having twist but in an amount such that primary reliance for elas-' ticity and spring return is placed upon the physical properties of the thread itself, rather than' upon the twist. The amount of twist desirable for any particular use may be readily determined 15 by experiment. The minimum amount of twist should not be much below six turns to the inch and may be a number of times that amount. Such a thread will be substantially circular in cross section and will present a minimum surface to therubber per unit of denier, and similarly the number of filaments exposedto the action of the rubber will be at a minimum per unit of denier, leaving by far the greatest possible number of filaments unafiected by the rubher and free to roll upon one another in the flexing incident to service.

My invention, however, is not to be understood as excluding cabling of the thread, for the advantages of my invention can be obtained, although to less degree, by employing cabling. Thus, using a 4000 denier yarn again as an example, I may employ say three threads of about 1250 denier each or two threads of about 1900 denier each and cable these.

In each of these instances, it will be seen that each thread is composed of a great multiplicity of filaments as contrasted to the threads heretofore employed, so that while the surface presented by such a cabled 40 thread is greater and the number of filaments exposed to the action of the rubber is also greater than in the single thread, nevertheless, as contrasted to the cabled thread first described, the

amount of surface exposed and the number of filaments exposed to the rubber are much less. Here, again, as contrasted with the first thread described, by far the great number of filaments are unaffected and left free to roll upon each other. 1

According to this aspect o" my invention, therefore. I contemplate a thread either lightly or heavily twisted, in which by far the greatest number of filaments are left unaffected by the rubber.

(The twist given 35 While I have described my invention primarily in connection with cord tires, it will be obvious that the invention may have other uses. Similarly the specific examples of denier given are those which are particularly useful in cord tires. The denier may be many times more or even considerably less, depending upon the particular use for which the rayon is to be employed.

I prefer to use cuproammonium thread as it lends itself well to the production of non-adherent filaments, particularly when following the procedure of the patent to' Furness No. 1,770,750, which I prefer.

I claim:

1. As a new article of manufacture, a rayon yarn for reinforcement in rubberized products, such as cord tires, heavy duty tires'and the like. of from approximately 1000 to 4000 denier or more,

comprised of a bundle of filaments of from approximately 1% to approximately 2 denier, the bundle being twisted into a single thread.

2. As a new article of manufacture, a rayon yarn for reinforcement in rubberized products such as cord tires, heavy duty tires and the like, of approximately 4000 denier or more, comprised of a bundle of approximately 1300 filaments or more, the bundle being twisted into a single thread within the neighborhood of 6 turns per lineal inch of thread, at least.

3. As a newarticle of manufacture, a rayon yarn for reinforcement in rubberized products, such as cord tires, heavy duty tires and the like,

more, comprised of a bundle of non-adherent filaments of from approximately 1% to approximately 2 denier, the bundle being twisted into a single thread.

4. As a new article of manufacture, rayon yarn reinforcement for rubberized products, such as cord tires, heavy duty tires and the like, said reinforcement including a bundle of filaments twisted together, the filaments being of from approximately 1 to approximately 2% denier, and the number of filaments twisted together in the bundle being sufilcient to give the bundle at denier upwards of about 1000.

5. A rubberized product having rayon yarn reinforcement embedded therein, said reinforcement including a bundle of about 400 or more filaments so twisted together as to give the bundle a substantially circular cross-sectional shape as compared with cabled yarn, the bundle having a denier upwards of about 1000, whereby only a small proportion of the total number of filaments in said bundle are exposed to the rubber.

6 A rubberized product having reinforcement embedded therein composed of separate heavy denier single rayon yarns, each yarn comprised of a great multiplicity of fine and relatively elastic non-adherent filaments so bundled together in direct and non-adherent contact with each other as to expose to the rubber, only such portion of the total number as are necessary to form a relatively thin encasement for the remainder of said filaments, leaving said remainder free of any bond between them. EDWARD G. BUDD. 

